This invention relates to apparatus for converting an optical theodolite into a laser theodolite.
Optical theodolites and laser theodolites are well known.
There are many applications where a theodolite may be used as a pointing device when precision azimuth and elevation locations of a point are desired. If an optical theodolite is used, at least two persons are required and lots of patience. One person has to operate the optical theodolite, whilst the other person has to mark the point under guidance from the person operating the optical theodolite. It is therefore preferable to use a laser theodolite. The laser theodolite points a laser which gives a spot on the place to be marked. Thus only one person is required to operate the laser theodolite and considerable time is saved.
The known laser theodolites are expensive. Most precision laser theodolites are designed for long range day light use as surveying instruments. The laser usually consists of a high output device built into the laser theodolite. The result is a laser theodolite which is expensive.
Range finder instruments are also known. These known range finder instruments are often designed with built in lasers and they serve a unique purpose for measuring distance. Even if the range finder instruments are considered as suitable for attachment to optical theodolites, the range finder instruments have unique properties which make them expensive for consideration as attachment to optical theodolites.
Low cost optical theodolites are known. A retrofit laser attachment for converting such low cost optical theodolites into laser theodolites is known. However, the retrofit laser attachment is expensive and it is designed for a specific theodolite. The known retrofit laser attachment has also been designed for long range day light use as a surveying instrument.
There is a need for apparatus for converting an optical theodolite into a laser theodolite, which apparatus is inexpensive, easily mountable to an optical theodolite, and accurate. It is an aim of the present invention to provide such apparatus.
Accordingly, in one non-limiting embodiment of the present invention there is provided apparatus for converting an optical theodolite into a laser theodolite, which apparatus comprises a laser diode adapter for connection to the optical theodolite in place of an eyepiece of a telescope of the optical theodolite, and driver means for the laser diode adapter; the laser diode adapter comprising a housing, a laser diode, a holographic image reshaping lens, and a focusing lens in the housing, and an externally threaded male portion for screwing into the telescope in place of the eyepiece; and the driver means having securing means for securing the driver means to the optical theodolite remote from the laser diode adapter.
The apparatus of the present invention can be relatively inexpensively produced as compared with known apparatus. The apparatus is easily able to be mounted to an existing optical theodolite. Still further, the apparatus is able to be conveniently portable. If desired, the apparatus may be low powered for short range low light.
In a first form of the apparatus of the invention, the laser diode adapter has the above mentioned components. The apparatus may then be one in which the laser diode adapter and the driver means are constructed such that they do not interfere with the required operational movements of the formed laser theodolite. In a second form of the apparatus, it may be one in which the laser diode adapter includes a beam splitter and an extension lens in the housing, and in which the laser diode adapter and the laser means are constructed such that they retain the optical sighting ability of the telescope of the formed laser theodolite.
The apparatus may be one which is able to be attached to the formed laser theodolite between the telescope and the eyepiece or between the formed laser theodolite diagonal eyepiece and the eyepiece.
The apparatus may include adjuster means for adjusting the laser diode in the housing such that the laser diode is able to be aligned with the telescope""s optical path.
Preferably, the adjuster means are screws. Other types of adjuster means may however be employed.
In the above mentioned first form of the apparatus, the apparatus may be one in which the externally threaded male portion is on a front face of the housing. In the above mentioned second form of the apparatus, the apparatus may be one in which the externally threaded male portion is in the front face of the housing and an internally threaded female portion is in the back face of the housing. Other arrangements may however be employed.
Preferably, the securing means is a releaseable securing means for enabling the driver means to be removed from the laser theodolite and stored when the apparatus is not in use.
Preferably, the releaseable securing means is a male and female fabric patch securing means. Also, preferably, the male portion of the male and female fabric patch securing means is attached to the driver means, and the female portion of the male and female fabric patch securing means is attached to the theodolite. Other types of securing means may be employed if desired.